JP7087817B2 - How to cut the cover glass - Google Patents

Description

The present invention relates to a method for cutting a glass plate, and relates to a cutting method for cutting a glass plate by three steps of scribing, hollow cutting, and stress cutting.

As the amount of information increases, the need for high-performance displays is increasing, and many cover glasses having a flat main surface have been developed for mobile phones, mobile tablets, in-vehicle displays, and the like. On the other hand, in recent years, the demand for cover glass having a complicated shape such as in-curve and cover glass having a curved surface is increasing, and advanced processing technology for cutting the glass plate with the same accuracy as ordinary flat glass is available. It has been demanded. Further, not only the processing accuracy but also the improvement of the processing speed is required.

When cutting flat glass, a method of forming a cutting line by using scribing and breaking it is known. However, when a glass plate having a curved surface (hereinafter referred to as curved glass) is broken by applying stress after scribing, glass contact occurs between the broken glass piece and the glass plate, so that the glass can be broken. Can not.
In addition, even if it is flat glass, when cutting out a glass plate having a complicated shape such as an in-curve, especially when cutting out the glass plate at an acute angle with respect to the end face of the glass plate, cracks that are the starting points of breakage occur in the glass plate. , There was a problem that scribing was not available.

When cutting curved glass, it is the mainstream to cut it by hollowing out with a grindstone. Further, when cutting curved glass, chipping is likely to occur when the curved glass is hollowed out using a grindstone in the same manner as flat glass, and it is difficult to process with high accuracy. Further, if the feed rate of the grindstone is increased in order to improve the processing speed, the size of the chipping becomes large and the yield deteriorates.

Therefore, when the object to be processed is curved glass, or when the glass to be cut out has a complicated shape such as in-curve even if it is flat glass, the processing speed is excellent with the same accuracy as when cutting conventional flat glass. There is a demand for a cutting method for cutting a glass plate.

Japanese Patent Application Laid-Open No. 2003-277088 Special table 2017-526603 JP-A-2017-132864

When cutting curved glass with high accuracy and high speed, or when cutting a glass plate having a complicated shape such as in-curve from flat glass, it is necessary to prepare the conditions for processing the glass plate in the same manner as flat glass.

In Patent Document 1, at least one notch is made in flat glass by a disk-shaped blade, a cut line is drawn by connecting the cut end and the side edge or the cut end of the thin plate glass with a glass cutter, and the cut and the cut line are drawn. Disclosed is a method for cutting glass by folding a portion surrounded by. However, when making a notch in a glass plate with a disk-shaped blade, only a straight notch can be made, so it is effective when the corner of the notch is made a right angle, but it is not suitable for processing complicated shapes. Further, Patent Document 1 discloses a process of drilling a hole in a glass plate having a thickness of 3 mm by a core drill, but discloses that the glass plate having a thickness of 2 mm is cut by a wheel blade or a grindstone without using a core drill. ..

Patent Document 2 includes a step of marking a cutting line on the surface of glass using a cutting tool and a cutting step of applying a local support means to the opposite surface in line with the cutting line, and the local support means is provided on the opposite surface. Disclosed is a method of cutting glass, characterized in that a complex shape is cut out of a glass plate by a method comprising moving and applying to the length of the cutting line. However, the method described in Patent Document 2 does not process curved glass, and since a pressing means is used on the opposite surface of the cut line, a jig for fixing the glass from the back surface is required.

Patent Document 3 discloses a structure of a curved glass processing apparatus in which a cutter is pressed against a curved glass and the cutter tool and the glass plate are relatively moved to form a cutting line on the glass plate. However, Patent Document 3 only discloses a step of performing stress cutting after forming a cutting line using a cutter tool, and does not disclose a cutting method for cutting curved glass by both a hollow cutting with a grindstone and a scribing step. ..

The above-mentioned Patent Documents 1 and 2 do not assume that curved glass is a processing target. Moreover, the processing method does not use the three steps of scribing, hollow cutting, and stress cutting. Further, Patent Document 3 discloses a case where bent glass is cut by using scribing, but when cutting a glass plate having a complicated shape such as an in-curve, cutting by scribing alone makes the folding process complicated and realistic. It is difficult to do.

The present invention provides a method for cutting a glass plate with high accuracy and high speed by using three steps of scribing, hollow cutting, and stress cutting. The present invention provides a method for cutting a glass plate having excellent processing accuracy and processing speed, particularly when cutting curved glass or when cutting a complicated shape such as an in-curve from flat glass.

That is, the present invention is as follows.
1. 1. It is a cutting method that cuts a glass plate.
The cutting method is
The process of forming a cutting line by scribing and
The process of hollowing out and cutting
It is characterized by having a step of stress cutting along the cutting line.
How to cut a glass plate.
2. 2. The method for cutting a glass plate according to 1 above, wherein the hollow cutting is a point processing.
3. 3. The method for cutting a glass plate according to 1 above, wherein the scribing is performed by any of a cutter wheel, a diamond tip, a pulse laser, or thermal stress.
4. The method for cutting a glass plate according to 1 above, wherein the hollow cutting step is performed by a grindstone in which a high-speed spindle is driven by electricity or compressed air.
5. The method for cutting a glass plate according to 1 above, wherein the hollow cutting is performed by any of high-pressure water, fusing, or a pulse laser.
6. The method for cutting a glass plate according to 1 above, wherein the stress cutting is performed by applying bending stress or thermal stress.
7. The method for cutting a glass plate according to 1 above, wherein the scribing and the hollow cutting step are performed by the same device.
8. The method for cutting a glass plate according to any one of 1 to 7, wherein the glass plate is a glass plate having a curved surface.
9. The method for cutting a glass plate according to any one of 8 above, wherein the glass plate having a curved surface has a curved surface having a single curved surface or a compound curved surface.
10. A glass plate cut by a glass plate cutting device, wherein the glass plate is a glass plate having a curved surface, and the size of chipping generated at the time of cutting is in the range of 0.01 to 0.4 mm.

According to the present invention, by hollowing out the glass plate, a certain gap required for folding the glass plate after scribing is formed by a free curve. Therefore, since the glass does not come into contact with the glass piece, even a glass plate having a curved surface such as a single curve or a compound curve can be cut with high accuracy and at high speed. Furthermore, even when cutting out a glass plate with a complicated shape such as an in-curve, by incorporating scribing, the process distance of the hollow cutting process is shortened, the throughput is improved, chipping is reduced, and stress cutting is close to a mirror surface. You can get the end face.

The above-mentioned hollow cutting also includes a step of penetrating with a grindstone or the like (hereinafter referred to as point processing). The gap formed by the point processing also has the effect of preventing contact between the glass plate and the broken glass piece, similar to the gap formed by the hollow cutting. Then, after forming a gap by point processing, a cutting line is formed and broken so as to connect the gap by scribing, which has the effects of improving the throughput and reducing the chipping.

In addition, by increasing the number of revolutions using a high-speed spindle, the size of chipping that occurs when cutting a glass plate with a grindstone is also reduced, so further machining accuracy and machining can be achieved by adjusting to a series of processes from scribing to stress cutting. It is possible to improve the speed.

It is a top view which shows one Embodiment of the glass plate cut by this invention. It is a figure for demonstrating the glass plate cutting apparatus used in this invention. It is a flowchart of this invention which showed the procedure of cutting a glass plate by this invention. FIG. 4A is a diagram showing a procedure for cutting a glass plate by a conventional technique, FIG. 4B is a diagram showing a procedure for cutting a glass plate using the present invention, and FIG. 4C is a diagram showing a procedure for cutting the glass plate. ) Is a diagram showing a procedure for cutting a glass plate using the present invention. It is explanatory drawing which shows the positional relationship between a glass plate and a cutter tool. FIG. 6A is an explanatory diagram showing the positional relationship between the glass plate and the grindstone, and FIG. 6B is an explanatory diagram showing the gap d when the glass plate is hollowed out and cut by the grindstone. It is explanatory drawing which shows the process of breaking a glass plate by stress cutting.

The definitions of the following terms apply throughout the specification and claims.
The "plane" means a portion having an average radius of curvature of 100,000 mm or more.
The "curved surface" means a portion having an average radius of curvature of less than 100,000 mm.
"Point processing" means a processing method for penetrating a glass plate using a grindstone or the like.

Hereinafter, the method for cutting the glass plate of the present invention will be described with reference to the drawings.
<Glass plate>
FIG. 1 is a plan view according to an embodiment of curved glass 10 cut by the present invention.
As shown in FIG. 1, the glass plate cut by the present invention has a curved surface, and has a first surface 11, a second surface 12 facing the first surface 11, and a first surface 11 and a second surface 12. It comprises a glass plate 10a having at least one end face 13 to be connected.
The glass plate 10a in the present specification means a plate-like body having a length in the longitudinal direction or the lateral direction of the first surface 11 and the second surface 12 larger than the thickness of the end surface 13. ..
Of the two main surfaces of the glass plate 10a, which main surface is used as the first surface or the second surface is not particularly limited. For example, the surface on the side that becomes the display surface when used as the cover glass of the display, that is, the surface on the side exposed to the outside is referred to as the first surface of the glass plate 10a. In this case, the surface facing the display surface is the second surface of the glass plate 10a.

Further, it is preferable that the end face 13 of the glass plate 10a constituting the curved glass 10 has a small thickness for the following reasons. By reducing the thickness, the mass of the glass plate 10a becomes smaller. The absorbance of the glass plate 10a in the thickness direction is proportional to the thickness. Therefore, by reducing the thickness, the absorbance can be reduced and the visible light transmittance in the thickness direction of the glass plate 10a can be increased, so that the visibility is improved.

The curved glass 10 of the present embodiment may be a glass plate that partially forms a flat surface. The average thickness of the curved glass plate is 5 mm or less. From the viewpoint of weight reduction and sensing of a touch panel or the like, the average thickness of the glass plate forming the curved glass 10 is preferably 3 mm or less, and more preferably 1.5 mm or less. On the other hand, in order to maintain the appearance quality, the average thickness of the glass plate is preferably 0.5 mm or more, more preferably 0.7 mm or more. Further, it is preferable that the curved glass 10 of the present embodiment has little variation in the thickness of the curved surface of the glass plate because variations in the transmittance of the glass plate and the like are suppressed and visibility is improved.

<Glass plate cutting device>
FIG. 2 is a diagram for explaining the glass plate cutting device 200 used in the present invention. The glass plate cutting device 200 supports the glass plate 205 on the base 61, and aims to cut the glass plate 205 into a desired shape by a cutter tool 43 or a grindstone 47. The material of the grindstone 47 may be metal or resin. The base 61 has a positioning pin (not shown) for positioning the glass plate 205, and the positioning pin suppresses the misalignment that occurs when the glass plate 205 is cut. The cutter tool 43 or the grindstone 47 is fixed to the collet chuck 83, and the spindle 41 supporting the collet chuck 83 can be horizontally moved in the X-axis or Y-axis direction to cut the glass plate 205 into a desired shape. The cutter tool 43 connected to the spindle 41 performs a scribing step of forming a cutting line on the glass plate 205, and the cutter tool 43 is replaced with a grindstone 47 to perform a hollow cutting step of the glass plate 205.

In the present specification, the vertical direction which is the axial direction of the spindle 41 shown in FIG. 2 is the Z-axis direction, the paper vertical direction of FIG. 5 is the Y-axis direction, and the left-right direction of FIG. 2 orthogonal to the Y-axis and the Z-axis is. It is in the X-axis direction. Further, the rotation axis of the spindle 41 is defined as the θ axis.

The cutter tool 43 can be selected according to the properties of the glass plate 205 to be cut, and for example, a cutter wheel, a cutter pin, or a diamond tip may be used. Specifically, Penett (registered trademark), APIO (registered trademark) manufactured by Samsung Diamond Industry, carbide cutters and the like can be used. However, it is possible to use a cutter wheel because it is inexpensive, has abundant experience in cutter cutting technology, can easily optimize the conditions for forming cutting lines, and can reduce chipping that occurs on the glass plate. preferable.

In the cutter wheel, the cutting edge angle α, which is the opening angle of the inclined surfaces on both sides in the axial direction of the circumferential ridgeline, is preferably 100 to 160 °, more preferably 110 to 150 °, and even more preferably 115 to 145 °. A blade having a small cutting edge angle is preferable for a glass plate 205 having a thin thickness, and a blade having a large cutting edge angle is preferable for a glass plate 205 having a thick thickness.

When a glass plate of 0.7 to 3 mm is molded to give a curved surface shape, a slight plate thickness deviation occurs, but the cutting edge angle α that can form a highly accurate cutting line even if a plate thickness deviation occurs is 120 to It is 145 °. Further, in the cutter tool 43, the turning position around the θ axis is controlled by driving the spindle 41 so that the machining feed direction is directed at the time of machining.

The glass cutting device 200 includes an auto tool changer 57 in the device. By replacing the cutter tool 43 with the grindstone 47 by the auto tool changer 57, the work time required for replacement with the grindstone 47 can be shortened, and the hollow cutting process for more efficiently forming the cutout line formed on the glass plate 205 can be performed. It can be carried out.

The auto tool changer 57 includes a pair of arms 91 having a tool holding portion for holding the tool at the tip thereof, and an exchange driving unit 95 for rotating and moving the pair of arms 91 around the shaft 93 in the axial direction. To prepare for. The cutter tool 43 held by the collet chuck 83 of the spindle 41 at the retracted position shown by the dotted line in the figure can be attached and detached by the exchange drive unit 95. That is, the auto tool changer 57 can selectively attach and remove a desired tool from a plurality of types of tools prepared in the tool stocker (not shown) to the collet chuck 83, and automatically replaces the tool of the collet chuck 83. Do it at. For example, when performing hollow cutting with the grindstone 47, the cutter tool 43 and the grindstone 47 are quickly replaced by holding the grindstone 47 in the tool stocker.

The grindstone 47 connected to the spindle 41 performs a hollow cutting step of hollowing out and cutting the glass plate 205. It is preferable that a plurality of types of grindstones 47 are provided according to the required processing accuracy. Initially, it is processed with a coarse grindstone, and then gradually processed with a fine grindstone to finish the desired surface texture. As the material of the coarse grindstone, alumina, cBN (cubic boron nitride), green carbide, diamond and the like can be used, and the material is preferably diamond in terms of grindability and hardness. The roughness of the coarse grindstone is preferably # 80 to # 400, more preferably # 100 to # 350.

Further, the glass plate 205 can be stress-cut by applying stress to the glass plate 205 and folding it along the cutting line formed by the cutter tool 43. In addition, the outer peripheral finishing of the cut end face 45 of the glass plate 205 may be performed by the grindstone 47 connected to the spindle 41.

The curved glass processing apparatus 200 is preferably a machine tool such as a multi-axis machining center numerically controlled by a computer. By numerically controlling the glass plate 205 by a computer, it is possible to stably perform a series of operations of the glass plate cutting process including the positioning of the glass plate 205 and the outer peripheral finishing.

<Glass plate cutting process>
FIG. 3 is a flowchart showing a cutting process for cutting the glass plate 205 according to the present invention. FIG. 3A shows a case where the glass plate 205 is first hollowed out using a grindstone 47 and then a cutting line is formed by scribing, and FIG. 3B shows a case where the cutting line is first formed by scribing. Is shown, and later, a case is shown in which a grindstone 47 is used to perform hollow cutting. When hollowing out using the grindstone 47, it is preferable to perform spark-out for several seconds at the end point. Spark-out is the work performed at the final stage of grinding, and means that the grindstone is rotated without making a cut and the machining is continued until the sparks and grinding noise caused by the grinding disappear.

When stress cutting is performed along the cutting line after hollow cutting with a grindstone 47 or after scribing, the stress cutting is performed by applying bending stress or thermal stress. It may be folded using a pressure-adjustable pressing means, or it may be folded by hand or by heating with a laser.

When cutting a glass plate, the steps for controlling the takt time are often detachment / attachment of glass, cutting of in-curve or out-curve, and other peripheral finishing. This also applies when processing curved glass. The present invention greatly contributes to the improvement of the tact time of the entire process in order to shorten the time required for in-curve or out-curve processing.

FIG. 4A is a diagram for explaining a method of cutting the curved glass 10 by using a conventional method of cutting a glass plate, and an arrow I (dashed-dotted line) indicates the cutting direction. In the conventional glass cutting method, the curved glass 10 is hollowed out and cut using a grindstone 47 as shown in FIG. 4 (A). The machining center equipped with the grindstone 47 moves along a preset course while hollowing out and cutting the glass plate at a predetermined speed.

FIG. 4B is a diagram for explaining a method of cutting a curved glass 10 by using the method of cutting a glass plate of the present invention. The method for cutting a glass plate of the present invention includes a step of scribing the curved glass 10 to form a cutting line, a step of hollowing out the curved glass 10, and a step of stress cutting along the cutting line of the curved glass 10. , Process the glass plate. The arrow I indicates the case where the curved surface is hollowed out and cut using the grindstone 47, and the arrow II (broken line) indicates the case where the curved surface is scribed to form a cutting line. The procedure of arrows I and II can cut the bent glass 10 with high accuracy and high speed regardless of which comes first. Since the distance cut by the glass plate cutting method of the present invention is shorter than the distance cut by the conventional grindstone 47, the required processing time is shortened.

Further, in the hollow cutting according to the arrow I, the hollow cutting is performed so as to form a gap of at least 0.5 mm between the broken glass piece and the glass plate. When breaking a glass plate with a small radius of curvature, it is possible to prevent the glass from coming into contact during stress cutting by increasing the gap.

FIG. 4C is a diagram for showing a procedure for cutting using the glass plate cutting method of the present invention, including a step of penetrating the glass plate by point processing. The present invention comprises a step of scribing the curved glass 10 to form a cutting line, a step of forming a gap in the curved glass 10 by penetrating processing, and a step of stress cutting along the cutting line of the curved glass 10. It is characterized by processing a plate. The arrow I and the processing mark III in FIG. 4C are gaps formed by point processing, and the arrow I is a gap formed by the above-mentioned arrow I in FIG. 4B by point processing. Further, in the point processing, even when the intersections of the cutting lines formed by scribing do not sufficiently intersect, as in the processing mark III, the intersections can be auxiliary and smoothly processed. Even by point processing, it is possible to create a gap in which the glass on both sides of the cutting line required for stress cutting does not contact, and prevent the glass from contacting.

<Scribbing>
FIG. 5 is an explanatory diagram showing the positional relationship of the cutter tool 43 with the base 61 in the scribing of the glass plate 205.
When the cutter tool 43 is moved along the planned line of the cutting line by driving the spindle moving stage 55 with the glass plate 205 positioned on the base 61, the cutting line 87 is formed on the glass plate 205. .. The groove depth of the cutting line 87 is preferably 5% or more and 20% or less of the thickness of the glass plate 205. By setting the groove depth, the scratch depth is appropriate for cutting glass, and cracking of the glass plate 205 at an undesired position can be suppressed.
On the other hand, scribing can also be performed using alternative means such as a cutter tool 43, a pulsed laser, or thermal stress.

<Cut out>
FIG. 6A is an explanatory diagram showing the positional relationship of the grindstone 47 with the base 61 in the hollow cutting of the glass plate 205.
As shown in FIG. 6B, the glass plate 205 supported by the base 61 is cut out so as to form a gap d so that contact does not occur between the glass plate and the broken glass piece. Glass. The gap d is the shortest distance between the two cut end faces formed by the hollow cut. The gap d is a distance at which the glasses on both sides of the cut surface do not contact, preferably at least 0.1 mm or more, and more preferably 0.5 mm or more. When the glass is broken in the direction perpendicular to the bending direction of the glass plate 205, it is preferable that the smaller the average radius of curvature of the glass plate 205, the wider the gap d is formed. By doing so, it is possible to form a cut surface close to a mirror surface by stress cutting, which will be described later, while suppressing contact when the glass plate 205 is folded. As shown in FIG. 6A, the base used for hollow cutting preferably has a groove 32 and has a structure in which the grindstone 47 does not interfere with the base. Even in the case of hollow cutting by point processing, it is preferable to have the groove 32 as a base structure.
On the other hand, hollow cutting can also be performed by alternative means such as high-pressure water, fusing, and pulsed laser.

<Stress cutting>
FIG. 7 is a process explanatory diagram showing a procedure of stress cutting. As shown in FIG. 7, the glass plate 205 fixed on the base 61 is folded by applying stress. The stress cutting may have a structure in which the folding step can be continuously carried out while the glass plate 205 having the cutting line formed by scribing is supported by the base 61.

Since stress cutting can be performed independently of the spindle 41 side after cutting wire machining, the time required from the completion of cutting wire machining to the start of stress cutting can be shortened, and the tact time required for machining can be reduced. Can be improved. Further, in stress cutting, since the curved glass processing apparatus 100 is configured by a commonly used machining center, curved glass can be processed with high production efficiency and low cost. In this case, it is efficient to perform cutting line processing and stress cutting by scribing in the same device, and for example, it is preferable to place a glass plate on the above-mentioned machining center.

Furthermore, since the cutting line is formed using an inexpensive cutter wheel that has abundant cutting records with a cutter, the cutting line processing conditions can be easily optimized using abundant data, and the chipping that occurs in the glass plate can be reduced. As a result, high cut surface quality can be stably obtained at low cost.
Further, according to the above-mentioned glass processing apparatus 200, the glass plate 205 can be folded after forming an appropriate gap by hollow cutting, which is particularly effective when the glass plate 205 has a curved surface.
On the other hand, stress cutting can also be performed by applying bending stress or thermal stress.

The feed rate in the XY plane when forming a cutting line by scribing actually depends on the acceleration of the equipment, but in the straight part, the maximum feed rate is preferably 20000 mm / min, and 5000 to 10000 mm. / Min is more preferable. This is because stable continuous machining is possible in a long straight portion, and even if the feed rate is increased, the reduction in machining accuracy is small, so shortening the machining time is prioritized. On the other hand, in the curved portion, the maximum feed rate is preferably 10000 mm / min, more preferably 1000 to 5000 mm / min. This is because it is difficult to obtain the effect of increasing the machining speed in the short straight portion and the machining accuracy is highly dependent on the machining speed in the curved portion, so that it is prioritized to obtain stable machining quality. The speed of the straight part and the curved part can be set within a range in which the acceleration of the equipment can be maximized according to the mileage at the time of cutting. For example, when the glass plate 205 is 500 mm × 400 mm, it can be set to about 5000 mm / min for the straight portion and about 1000 to 2000 mm / min for the curved portion.

The cut end surface 45 of the glass plate 205 cut by the above-mentioned folding step may be subjected to outer peripheral finishing by a rotationally driven grindstone 47. After the outer peripheral finishing process is completed, the glass plate 205 is removed. This completes the processing of the glass plate 205.

As described above, the present invention is not limited to the above-described embodiment, and can be modified or applied by those skilled in the art based on the mutual combination of the configurations of the embodiments, the description of the specification, and the well-known technique. Is also the subject of the present invention and is included in the scope for which protection is sought.

First, a commercially available flat glass (product name: Dragontrail (registered trademark), manufactured by AGC Inc., width 220 mm, length 650 mm, plate thickness 2.0 mm) was prepared. The prepared flat glass was heated to 720 ° C. to soften it, and molded by its own weight bending so as to be compatible with the prepared mold to prepare a curved glass. The radius of curvature of the produced curved glass was 1750 mm.

Next, the glass plate 205 was placed on the base 61, and the glass plate 205 was positioned by the positioning pin. After confirming that the glass plate 205 was fixed, the grindstone 47 was attached to the machining center and in-curve cutting was performed. For the grindstone 47, commercially available grindstones (# 100P, # 325M manufactured by Tokyo Diamond Tool Mfg. Co., Ltd., # 200M manufactured by Noritake Co., Ltd., all of which are made of single crystal diamond (C)) are prepared and curved glass. The relationship between the feed rate and the chipping was measured while hollowing out the 205.

Next, the grindstone 47 was replaced with the cutter tool 43 by the auto tool changer 57, and the cutter tool was moved while being pressed against the glass plate 205 to perform scribing. The cutter tool used was a commercially available cutter wheel (cutter type: Penett (registered trademark) -SC (manufactured by Samsung Diamond Industry), wheel outer diameter 3 mm, wheel thickness 0.65 mm, wheel inner diameter 0.8 mm, cutting edge angle 115). °) Was used.

After scribing, stress cutting by hand folding was performed along the cutting line formed on the glass plate.

Table 1 shows the results of cutting under the above conditions. Comparing the size of chipping caused by hollow cutting with a grindstone and the size of chipping caused by stress cutting, the chipping caused by the former is a grindstone with a grindstone diameter # 100 and φ3 at a rotation speed of 25,000 rpm and a feed rate of 200 mm / min. Although it was about 0.8 mm, the size of chipping caused by stress cutting after scribing was about 0.2 mm. Furthermore, when the size of the chipping was measured by changing the diameter of the grindstone and the type of grindstone, if the grindstone with a grindstone diameter # 200 and φ4 was hollowed out at a rotation speed of 25,000 rpm and a feed rate of 200 / min, the chipping size was 0. It will be 0.4 mm. Further, if a grindstone with a grindstone diameter # 325 and φ4 is hollowed out at a rotation speed of 50,000 rpm and a feed rate of 400 / min, the chipping size is reduced to 0.2 mm, and the grindstone with a grindstone diameter # 325 and φ4 has a rotation speed of 50,000 rpm. If the grindstone is cut out at a feed rate of 200 / min, the size of the chipping is reduced to 0.1 mm. The number of revolutions can be increased by driving the high speed spindle with electric or compressed air on the grindstone.

The shape of the cut end face 45 approaches a smooth end face such as the cut end face 45 by stress cutting by adjusting the diameter of the grindstone, the rotation speed of the grindstone, and the feed rate even if the cut end face 45 is cut by hollow cutting. .. That is, when the glass is hollowed out and cut under the condition that the size of chipping is small, and then the glass plate is cut by stress cutting after scribing, the cover glass having a complicated shape such as an in-curve or a curved surface is smooth. It is possible to manufacture a cover glass having a sharp cut end face. The size of chipping was measured with a stereomicroscope or a microscope, and the average value of variation was taken. The minimum value of chipping that can be measured by a microscope is 0.01 mm.

Further, the time required for cutting and forming the in-curve with only hollow cutting (feed speed 200 mm / min, total movement distance 1000 mm) for the curved glass 205 was about 300 sec (Table 2), but using the present invention. The time required to cut and form an in-curve on curved glass is 200 seconds (the time required for hollow cutting is about 60 seconds on two sides, and the time required for scribing and stress cutting combined is about 140 seconds). The tact time has improved.

Further, as a result of carrying out the present invention using a grindstone having a grindstone diameter # 200 as shown in Table 2, it was found that the frequency of occurrence of cracks, which is the starting point of fracture, is lower than that of grindstones having a grindstone diameter of other grindstones. By selecting a grindstone with a low crack occurrence frequency, it is possible to produce a cover glass with a low possibility of breakage.

Next, according to the procedure shown in FIG. 4B, curved glass prepared under the same conditions as in the above-described embodiment was scribbled, and then hollowed out using a grindstone 47 to perform stress cutting. At this time, as the grindstone 47, a # 200 metal grindstone (grindstone diameter φ4 mm) and a # 100 electrodeposition grindstone (grindstone diameter φ3 mm) were used.

The # 200 metal grindstone (grind diameter φ4 mm) has a gap of 4 mm, and the # 100 electrodeposited grindstone (grind diameter φ3 mm) has a gap of 3 mm. No glass contact occurred. By forming a sufficient gap, it is possible to perform stress cutting with a margin even on curved glass having a small radius of curvature. The gap width is appropriately adjusted according to the plate thickness of the curved glass and the radius of curvature.

In the example, in the glass cutting step, the scribing step was performed after the hollow cutting, but the hollow cutting step and the scribing step may be appropriately replaced according to the properties of the glass plate and the cutting line and the stress at the time of folding. The hollow cutting step and the scribing step may be alternately performed.

In the embodiment, curved glass is used as the glass plate, but the glass plate may be flat glass or glass having a curved surface.

10 Curved glass 10a Glass plate 11 1st surface 12 2nd surface 13 End surface 32 Groove 41 Main shaft
43 Cutter tool 45 Cut end face 47 Whetstone 55 Main shaft movement stage 57 Auto tool changer (tool replacement part)
61 Base 83 Collet chuck 87 Cutting wire 91 Arm 95 Replacement drive unit
I, II cut line
200 Curved glass processing equipment 205 Glass plate
d Gap

Claims (9)

It is a cutting method that cuts a glass plate.
The cutting method is
The process of forming a cutting line by scribing and
The process of hollowing out and cutting
It has a step of stress cutting along the cutting line and
The glass plate is a glass plate having a curved surface .
How to cut a glass plate. The method for cutting a glass plate according to claim 1, wherein the hollow cutting is point processing. The method for cutting a glass plate according to claim 1, wherein the scribing is performed by any one of a cutter wheel, a diamond tip, a pulse laser, and thermal stress. The method for cutting a glass plate according to claim 1, wherein the hollow cutting is performed by a grindstone in which a high-speed spindle is driven by electricity or compressed air. The method for cutting a glass plate according to claim 1, wherein the hollow cutting is performed by any one of high-pressure water, fusing, and a pulse laser. The method for cutting a glass plate according to claim 1, wherein the stress cutting is performed by applying bending stress or thermal stress. The method for cutting a glass plate according to claim 1, wherein the scribing and the hollow cutting are performed by the same device. The method for cutting a glass plate according to any one of claims 1 to 7, wherein the glass plate having a curved surface has a curved surface having a single curved surface or a compound curved surface. The method for cutting a glass plate according to any one of claims 1 to 8, wherein the size of chipping generated when the glass plate is cut is in the range of 0.01 to 0.4 mm.

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